When windows are installed in buildings, such as residential dwellings, they are installed in window openings. Replacement windows, as opposed to new residential windows, are usually installed in existing window openings. After the replacement window is installed, prepainted aluminum flashing is used to cover the gap between the new window and the existing siding, brick, or other exterior wall surface of the window opening.
One of the problems with the installation of replacement windows is that the cover or flashing for the opening or gap between the new window frame and the existing building wall needs to be secured or fixed in place, and in a manner which will prevent wind or moisture from entering the building. Further, the flashing must be attached in an aesthetically pleasing manner. Typical means for fastening the window flashing includes nailing, bending, and gluing the flashing in place. Nailing is often difficult because the wood surrounding the window opening may be old and rotten. Another method commonly used is merely caulking the flashing all the way around the perimeter of the window for a wind and water-tight joint. This old method of caulking can degrade after a period of weathering, resulting in air and water leaks into the building. It would be extremely desirable to provide an improved means for retaining the window flashing, particularly if such a method resulted in an easier installation method than methods heretofore employed.